Gas conditioning unit and method for drying gas



May 2'), 1957 J. s. HicKMAN 39320723 1T AND METHOD FOR DRYING GAS GAS CONDITION {NG 5 Sheets-Sheet l Filed June ATTORNEYS.

Mll 23, 96? .1.5. HLCKMAN 3,320,723

GAS CONDITIONING UNIT AND METHOD FOR DRYING GAS Fil'cd June 9, 1964 5 Sheets-Sheet 2 ATTORNEYS 23, 1967 1. s. HxcKMAN GAS CONDITIONING UNIT AND METHOD FOR DRYNG GAS 5 SheetS-Sheet 3 Filed June L), 1964 ATTORNEYS.

May 23, i967 J. s. HscKMAN f 3,320,723

GAS CONDITIONNG UNIT AND METHOD FOR DRYING GAS Filed June 9, 1964 5 Sheets-Sheet 4 \//4 ATTORNEYS May 23, i967 J. s. HicKMAN 3,320,723

GAS CONDITIONING UNIT AND METHOD FOR DRYING GAS Filed June D, 1964 5 Sheets-Sheet 5 5 Si k m www Ill I www W r wk l l M In m @y 20W M if United States Patent O 3,320,723 GAS CONDITIQNING UNIT AND METHOD FR DRYING GAS John S. Hickman, Shorewood, Wis., assigner, by mesne assignments, to Airtex Corp., Chicago, Ill., a corporation of Illinois Filed .lune 9, 1964, Ser. No. 373,622 12 Claims. (Cl. 55-32) This invention relates generally to an improved gas conditioning unit and method. More particularly, this invention relates to an improved chemical gas conditioning unit and method which permits the transfer of heat from one fluid to another at a rate greatly increased over that presently available.

Additionally, this invention can also be used for cooling or heating a gas, c g., air. Although the device can be employed for these two uses, it is not intended to limit the device to these uses alone.

A conventional method for dehumidifying and humidifying buildings, rooms and the like has been to spray a hygroscopic solution, eg., lithium chloride, over a contact-ing surface from above and allow the solution to fall by gravitation through a stream of air which is drawn in from the atmosphere. The effect has been an interchange of heat, moisture content and the like between these non-miscible fluids. Because the velocity of the gas being cooled has to be substantially reduced in order to avoid any substantial carry-over of solution spray into the duct network leaving the gas handling unit, conventional units are unable to cool large quantities of gas in a short period of time. Further, the deep coils required by conventional units inherently produce channeling of the solution which results in reduced eectiveness. Also, because of this low gas handling capacity, units presently available are extremely large in size necessitating the use of a great deal of construction material as well as an abundance of iioor space, both of which are important factors in the computation of the overall cost of a unit.

I have discovered a system where-in an improved chemical gas conditioner is used which permits the humidifying and dehumidifying of large quantities of gas at a greater rate than has been heretofore possible. Moreover, the apparatus of the present invention is reduced in size thus effecting an initial savings in cost brought about by a substantial reducion in material necessary to construct the unit. In addition, another savings is realized by the reduction in premium floor space required to install the unit. Further, my apparatus can also heat/ cool the gas to be treated.

Other features of my invention reside in the minimization of entrainment of hygroscopic solution in the cooled gas as it passes through the unit into the duct work and the elimination of channeling. Additionally, as a reconcentrator, my invention is used to concentrate the hygroscopic solution for reuse.

According to one embodiment of my invention, hygroscopic solution is sprayed onto the faces of multiple vanes in a rotary interchanger where it is centrifugally forced outwardly along the faces of the various vanes. Simultaneously, air or some other gas to be treated is drawn into the passages formed by the vanes and centripetally forced inwardly along the length of the passages into the unit from where it is discharged into a gas duct network where the gas is readily available for use, e.g., cooling a building, room or the like. Cooling water or other suitable cooling means is directed through the rotating unit by means of a pipe system which supplies water to a cooling liquid inlet chamber. The liquid in the chamber is passed through a cooling water circuit in a heat exchange relationship with the hygroscopic solution and gas passing through the passages formed by the vanes. With my invention, moisture absorption and gaS cooling occur at a rapid rate due to the flow, mass heat exchange relationship among the gas, hygroscopic solution and cooling liquid.

Other features and advantages are inherent in the structure claimed and disclosed, as will be apparent to those skilled in the art from the following detailed description in conjunction with the accompanying drawings wherein:

FIGURE 1 shows a front view of my chemical gas conditioning unit and system;

FIGURE 2 shows an enlarged fragmentary view of the cooling water inlet system;

FIGURE 3 is a sectional plan view taken along line 3-3 in FIGURE 1 showing the gas and hygroscopic solution passages and cooling water compartments;

FIGURE 4 is a sectional view taken along line 4 4 in FIGURE 2 showing the construction of the various sets of passages;

FIGURE 5 shows an enlarged fragmentary view of the spray shield;

FIGURE 6 shows the reconccntrator used in my gas conditioning system;

FIGURE 7 shows another embodiment of the cooling water inlet system which can be employed in my apparatus;

FIGURE S shows an embodiment of my invention showing the vanes shaped in the form of involutes, the arrow indicating the direction of rotation of the rotor;

FIGURE 9 shows a perspective view of the cooling water inlet and gas-solution passages molded or shaped into the desired form;

FIGURE l0 shows a fragmentary plan view of the periphery of the cooling water and gas-solution passages shown in the embodiment of FIGURE 9; and

FIGURE 1l is an enlarged fragmentary View of the cooling water and gas-solution passages taken along lines 11-11 in FIGURE 7 iReferring to FIGURE l, there is shown a chemical gas conditioning unit generally designated 10 comprising casing 11 which encloses rotor 12. Rotor 12 includes side plates 13, 14, and a plurality of vanes 15 forming passages 32, 33, the construction of which is described hereinafter, are attached between these plates by suitable means, eg., bolts 16 and nuts 17. Rotor 12 is fixed to hollow rotating pipes 7 and 18 which are coupled to cold Water rotor coupling 19 and hot water coupling 20.

Pulley 21 is fastened to pipe 7 near coupling 19 and is connected to a drive motor (not shown) by means of belt or belts 22. `Upon actuation of the drive motor, pipe 7 is rotated causing rotation of both rotor 12 and pipe 18, the rotor being keyed or rigidly fastened by other suitable means to the pipe. As shown in FIGURE 2, the rotating portion of unit 10 is supported within casing 11 by means of bearings 25 and 26 which are positioned within unit support pedestal 5. Coupled to the inlet end of pipe 7 is a stationary water inlet pipe 27 which receives cooling water or other cooling liquid from a suitable source, e.g., cooling tower, well or refrigerated water. The cooling water is pumped or drawn from pipe 27 into rotating pipe 7 where its progress is impeded by baiiie plate 29. Batlle plate 29 causes the water to be directed outwardly in chamber 30 formed by flanged baille plate 29 and side plate 14, baille plate 29 havinga plurality of openings 31 spaced along its radial length. Cooling liquid passes through openings 31 into hat exchange passages 32 formed in compartments 40, 4 42.

Side plate 14 has an inner diameter substantially equal to the outer diameter of pipe 7 and is welded in a lluid tight connection to the outer diameter of pipe 7. The flange portion located at the outer diameter of plate 29 is welded to plate 14. Plate 6, having a smaller outer diameter than the outer diameter of baffle plate 29, is flanged at its outer diameter and connected to bale plate 29 by a fluid tight weld.

Passages 32 are adjacent to gas intake and solution outlet passages 33 ras shown in FIGURE 4. Though passages 32 and 33 may be constructed by a number of different methods and have a number of different forms and shapes, I have shown, for purposes of illustration, passages 32 and 33 as being constructed from a series of spaced circular perforated plates 34 which are parallel to rotor side plates 13, 14. Between spaced plates 34 are located a series of circular corrugated panels 34a, each panel comprisingV a pair of spaced parallel webs 35, the ends of which terminate in flange 36 disposed at right angles to webs 35. The panels also have apertures therein and when the panels are in assembled condition, the apertures in plates 34 and panels 34a are axially aligned.

Located at right angles to plates 34 are a series of bale plates 37 which are positioned along the length of passages 32 as measured along the radial axis. In FIG- URE 2, four baille plates 37 are shown along the radial length of passages 32 separating these passages itnto compartments 40, 41 yand 42. It is appreciated that a greater or smaller number of plates 37 could be incorporated into unit depending upon what degree of dehumidification and/or cooling is desired. Each compartment has a liquid inlet opening and outlet opening as illustrated in FIGURE 2. The water in chamber y30 passes through openings 31, which serve as cooling waterv inlet means to compartments 40, 41 vand 42, traversing passages 32' in a sinusoidal flow path as depicted by arrows shown in FIGURE 2. Any number of flow patterns could be utilized depending upon the design of compartments 40, 41, 42. As the water traverses passages 32it is in a heat exchange relationship with the solution and gas flowing in adjacent passages 33.

After the cooling water completes its heat exchange relationship with the gas and solution and passes through the last passage 32, it ows into exhaust chamber which is formed by plate 13 and perforated plate 46. The heated water is then directed to water outlets 47 as seen in FIGURE 5. Outlets 47 are positioned adjacent plates 37, the outlets being spaced apart a distance equal to the width of the opening at the inward end of passages 2. The outlets are tubular members whose ends are fastened to retaining rings with the rings being attached by welding or the like to rotor 12. If desired, each tubular member forming an outlet 47 could be made integral with plate 37. The water passes through outlet 47 and outlet chamber 49 where its flow path is obstructed by baille plate 29 which directs the liquid into pipe 18 and into stationary outlet pipe 9 from where it is either exhausted from the system or recooled and again used in the system.

Hygroscopic solution enters unit 10 from solution inlet pipe 50. Solution under pressure travels along pipe 50, through a suitable number of branch pipes 51, 52.

Spaced along the lengths of the individual branch pipes are apertures 53, at which locations are connected, at right angles to the branch pipes, one end of nipples 54. The remaining end of each nipple is attached to spray shield 56, which is curved in such a manner that its longitudinal edges are in close proximity to Wall 57 of. water outlet 47. As shown in FIGURES 1, 2 and 6, nipples 54 are of varying lengths so as to effect a shield which tapers outwardly away from the longitudinal taxis of rotor 12 as it approaches chamber 49. The solution passes through apertures 53 and is sprayed out of nipples 54, which can have a nozzle-like construction, if desired, to provide a jet effect. The sprayed solution impinges on shield 56 from where it is directed into passages 33. The tapered shield reduces carry over of solution droplets to filter 70 and assures that the same quantity of solution is directed into each of the gas-solution passages 33. Centrifugal action caused by rotation of rotor `12 urges l the solution outwardly along the radial length of passages 33 forming a solution film on the faces of webs 35, flange 36 and plate 34 which make up the individual passages. Simultaneously, while the solution is forced outwardly along passages 33, air tobe humidified or gas to be absorbed is drawn into unit 10 through inlet duct 60 louvers 61 by .fan 64 located in the gas handling unit outlet. As the gas is drawn into passages 33, an interface contact occurs between the gas and hygroscopic solution whereby moisture is removed from the gas while at the same time the gas is cooled. Upon reaching the end of passages 33 furthest from pipe 7, the solution falls by gravitation to the bottom of casingrll where it is removed from casing 11 by passing through a suitable outlet such as pipe 80, to a storage tank and pump unit 62. From this tank, it can either be pumped back into the gas handling unit 10 through pipes 72 and 50, or to a reconcentrating unit where the solution is reconcentrated for use with the unit.

The lcountercurrent interface Contact between the gas to be dehumidi-ed or absorbed and hygroscopic solution effects linterchange of heat and moisture content. The introduction of the cooling water at a plurality of locations in the gas handling unit permits an increased heat exchange between the gas to be cooled and the hygroscopic solution.

Subsequent to its passage through unit 10, the cooled,

gas passes from passages 32 outof gas handling unit 10 -into gas outlet duct 63. In duct 63, lthe gas `passes through eliminator 70 which filters any solution out of the cooledgasfwhich might be entrained in the cool air. Fan 64 positioned on shaft 65 and drivenby means of pulley 67, belt 68 and `drive motor 69 causes the gas to be drawn into, through and out of unit 10.

The heated cooling water following -its re-entry into rotating pipe 7, which is coupled at one end to coupling 20 while the remaining end is rigid with outlet chamber 49, passes through stationary pipe 9 where it is exhausted from the system or pumped by suitable means to a cooling tower or heat exchanger (not shown) prior to its return as a cooling means for gas handling unit 10.-

FIGURE 6 shows an embodiment of a reconcentrator unit for reconcentrating diluted hygroscopic solution following yits use in gas handling unit 10.l The arrangement of the reconcentrator unit generally corresponds to unit 10 heretofore described. supplied to the unit throughpipe 91, thev steam flowing in a path through various compartments in a similar manner as described for the cooling liquid in unit 10, the steam being in a heat exchange relationship with diluted solution and air or other gas passing in adjacent passages. Air drawn in through inlet duct 93 and louvers 94 comes in interfacial contact with the heated solution which is being urged centrifugally outward along the faces of the vanes. The water in the diluted solution vaporizes and is carried along with the incoming air while the reconcentrated solution drops to the bottom of casing 95 where it passes through pipe 96 to a storage tank and pumping unit 97 for concentrated hygroscopic solution. The air which has been humidifed passes into duct 98 where it is exhausted. p

A valve arrangement has been shown in FIGURES 1 and 6` for controlling the operation of the unit. A dew cell (not shown) or other suitable means modulates valve 100. When the dew cell senses an increase in humidity, valve 100 is open to allow more concentrated solution to enter storage tank 62-of unit 10 and conversely, when a drop in humidity is sensed, valve 100` closes. Valve 101, which can be actuated by a oat indicator in storage tank unit 62, is opened or closed to maintain a constant solution level in unit 62 at all times. A density controller in storage tankand pump unit 97 modulates valve 102 in order to allowfthe proper concentration of solution to be constantly present.

It is appreciated that other means for driving the wa- In unit 90, however, steam is ter out of the solution can be employed aside from utilizing the reconcentration unit 90 described herein.

A heat exchanger 109 can -be employed between the respective storage tanks 62 and 97 for heating or cooling the solution as may be required in a particular application. It is appreciated that the heat exchanger and sumps shown in FIGURE 6y are only one of a number of systems which could be utilized for holding and transferring the hygroscopic solution.

Further, although liquid inlet and exhaust chambers have been employed in the drawings, a manifold arrangement could, if desired, be adapted by one skilled in the art for use with my apparatus in place of these chambers. Also vanes and side plates 13, 14 are shown bolted together. Other means of fastening these members could also be utilized, if desired.

In the discussion of the cooling means employed in the description of my gas conditioning unit 10, a number of compartments 40, 41, 42 were utilized to effect the sinusoidal How of the water throughout my apparatus. Moreover, in FIGURE 4, passages 32 and 33 were shown for purposes of illustration as having the same width and thickness dimensions.

Referring to FIGURE 7, there is shown another embodiment of a circuit for directing the flow of the liquid cooling means. The structure for this circuit is preferably rnade of plastic and comprises water inlet 110 which directs the water outwardly, as indicated by the arrows, along a plurality of baie plates 111. The water is then urged into water outlet channel 112, formed by plates 113 after which it then flows into chamber 49 as described previously. Bail-le plates 111 are lpreferably spaced about two inches apart from one another. Plates 111 and 113 have a depth of about '1A inch and are located at about right angles to plastic base sheet 114. It is apparent that many other circuits for directing the flow of the cooling water in my unit 10 could be designed by the artisan skilled in the art. Sheets 114 are stacked together with galvanized sheet 115, which have a plurality of ribs 116 formed therein, sheets 115 being disposed between sheets 114. The longitudinal edges of ribs 116 abut plastic base sheet 114 whereas base sheet 115 abuts the longitudinal edges of baffle plates 111 and 113. The depths of ribs 116 is approximately 1A; inch to '3/6 inch in order that passages 117 are provided with a large interfacial area between the two fluid streams. When sheets 114 and 115 are stacked together, FIGURE l1, and bent in a mold having the shape of involutes as depicted in FIGURE 9, the sheets are then fastened together by suitable fastening means. If desired, the plastic sheets 114 could be molded in an involute form originally, FIGURE 9, while metal sheets 115 could be stamped or rolled in the desired involute shape so that in a stacked condition, the involute form would have already been achieved.

If desired, plates 111, 113 and 116 could be made of different depths than set forth above and similarly baiiie plates 111 could be spaced closer or further apart than two inches, depending only -upon the particular design desired.

It has been previously described that fan 64 is so positioned as to draw gas to be treated in through duct 60 and out through duct 63. If desired, the hygroscopic solution and the gas to be treated could ow outwardly in the same direction and the water in the cooling circuit could flow inwardly to achieve a counterflow condition and a low leaving gas temperature. Fan 64 could be so positioned as to draw gas to be treated into rotor 12 through duct 63 so that both the gas to be treated and solution flow in the same direction.

If a lower leaving gas temperature is desired, a heat exchanger 108, which is supplied from the cooling water tower, could be placed in a heat exchange relationship with the solution passing to rotor 12 through line 50.

With my chemical gas conditioning unit and system,

the relative velocity between the liquid film and gas can be increased about seven times over conventional systems. Additionally, the heat transfer rate per square foot of wetted surface can easily be increased due to water passages 32 and the number of cooling water compartments 40, 41 and 42 in these passages. Moreover, because the gas conditioner now serves as a counterilow heat exchanger, entrainment of solution and subsequent carryover is no longer a problem.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:

1. A gas conditioning unit comprising:

a casing;

a rotor enclosed within said casing;

vanes connected to and extending outwardly from said rotor to form a plurality of a first set of gas and hygroscopic solution passages and a plurality of a second set of liquid passages;

drive means connected to said rotor for rotating said rotor within said casing;

liquid inlet means connected to said rotor for admitting liquid into said liquid passages;

liquid outlet means connected to said rotor for receiving said liquid from said liquid passages following a heat exchange with gas and solution in said gassolution passages;

gas inlet means connected to said casing adjacent the periphery of said vanes for admitting gas into said unit;

gas outlet means located on said casing near said rotor for receiving gas following its exhaustion from said unit;

hygroscopic solution inlet means positioned within said casing and located near the longitudinal axis of said rotor for introducing said solution into said gas-solution passages, whereby said solution is centrifugally urged outwardly along said gas-solution passages in a countercurrent interface contact with said gas when said rotor is rotated; and,

solution outlet means rigid with said casing for receiving solution following countercurrent interface contact of said solution with said gas.

2. A gas conditioning unit in accordance with claim 1 further including means connected with said solution outlet means for reconditioning said solution following its removal from said unit.

3. A gas conditioning unit in accordance with claim l wherein each of said gas-hygroscopic solution passages is alternately disposed between each of said liquid passages.

4. A gas conditioning unit in accordance with claim 1 further including a shield means connected to said solution inlet means for directing the solution into said gassolution passages.

5. A gas conditioning unit in accordance with claim 1 including baflie plates located at the respective ends of each of said liquid passages whereby said liquid will ow only within said passages.

6. A gas conditioning unit in accordance with claim 5 further including at least one baie plate disposed within said liquid passages to form separate compartments for the flow of said liquid.

7. A gas conditioning unit comprising:

a casing;

a rotor enclosed within said casing;

a plurality of rotatable vanes extending radially outward from said rotor, said vanes dening a plurality of liquid passages and a plurality of gas-hygroscopic solution passages, each of said liquid passages being disposed between a pair of said gas-solution passages;

liquid inlet and outlet means connected to said liquid passages for permitting the flow of liquid in a heat exchange relationship with said gas-solution passages; gas inlet means rigid with said casing for admitting gas into said unit; hygroscopic solution inlet and outlet means for admitting and exhausting solution into and out of said gas-solution passages; and, gas outlet means connected to said casing for removing said gas following moisture and heat transfer. 8. A gas conditioning unit according to claim 7 further including at least one baie positioned within each of said liquid passages for providing a plurality of compartments along the radial length of Said liquid passages.

9. A gas conditioning unit according to claim 7 Wherein said Vanes forming said gas-solution and liquid passages are made of plastic.

10. A gas conditioning unit according to claim 7 Wherein said vanes forming said gas-solution and liquid passages are shaped in the form of an involute.

11. A method for conditioning gas in accordance with the steps of:

centripetally urging said gas to he conditioned along a plurality of gas-hygroscopic solution vpassages in a gas conditioning unit;

centrifugally forcing hygroscopic solution along said gas-solution passages in interface contact with said gas; and,

simultaneously passing a liquid in a plurality of separate liquid passages disposed in indirect heat eX- t3 change relationship with said gas-solution passages so that liquid in each of said liquid passages is in heat exchange relationship with lsaid gas and solution. 12. kA method for conditioning gas in accordance with lclaim 11 further including the stepsof:

passing'said liquidin a direction transverse to the flow `of said gas and solution; and,.

directing said liquid passing in a heat exchange relationship with said gas and solution into a plurality of individual paths whereby each liquid path is in a heat exchange relationship with a portion of said gas and solution in said gas-solution passages.

References Cited by the Examiner UNITED STATES PATENTS 175,291 3/1876 Lount 55-29 689,246 12/1907 Theisen 55-86 1,057,613 4/1913 Baldwin 55-91 1,969,381 8/1934 Mullen et a1 55-29 2,230,088 1/1941 Podbielniak 55-32 2,235,322 3/1941 Martin 55-31 2,551,890 5/1951 Love 55-348 2,619,280 11/1952 Redlich 261--83 REUBEN FRIEDMAN, Primary Examiner.

I. ADEE, Assistant Examiner. 

11. A METHOD FOR CONDITIONING GAS IN ACCORDANCE WITH THE STEPS OF: CENTRIPETALLY URGING SAID GAS TO BE CONDITIONED ALONG A PLURALITY OF GAS-HYGROSCOPIC SOLUTION PASSAGES IN A GAS CONDITIONING UNIT; CENTRIFUGALLY FORCING HYGROSCOPIC SOLUTION ALONG SAID GAS-SOLUTION PASSAGES IN INTERFACE CONTACT WITH SAID GAS; AND, SIMULTANEOUSLY PASSING A LIQUID IN A PLURALITY OF SEPARATE LIQUID PASSAGES DISPOSED IN INDIRECT HEAT EXCHANGE RELATIONSHIP WITH SAID GAS-SOLUTION PASSAGES SO THAT LIQUID IN EACH OF SAID LIQUID PASSAGES IS IN HEAT EXCHANGE RELATIONSHIP WITH SAID GAS AND SOLUTION. 